The present invention pertains to an apparatus and method for continuously delivering sheets which are provided in successive stacks and, more particularly, to a system for delivering sheets in a continuous vertically ascending master stack from the top of which sheets are successively fed for continued processing.
In many sheet feeding systems, sheets are delivered to the system in discrete stacks, but it is desirable or even necessary to provide the continuous delivery of sheets in a stack so that individual sheets may be fed from the bottom of the descending stack or from the top of the ascending stack. In the former, discrete stacks may be continuously loaded into a feed hopper by any of a number of convenient means and the stack allowed to descend by gravity as sheets are fed from the bottom. In the latter situation, the continuous delivery of sheets in discrete stacks to form a continuously ascending stack from the top of which the sheets are fed is typically moire difficult. Nevertheless, sheet handling arid converting systems may inherently dictate the use of an ascending stack feeder.
It is the object of the present invention, therefore, to provide a lift apparatus and method for continuously delivering sheets which are supplied in successive stacks and, in particular, such a system which is especially adapted to handle solid fiberboard sheets.